368 CLIMATE AFFECTED BY CURRENTS. chap, xviii. 



larlj in width and depth with the Straits of Dover, the differ- 

 ence in depth not being more than three or four feet; so tliat 

 at the rate of upheaval, which is now going on in many pai'ts 

 of Scandinavia, of two and a half feet in a century, such 

 straits might be closed in 3000 years, and a vast accumulation 

 of ice to the northward commence forthwith. 



But, on the other hand, although such an accumulation 

 might spread its refrigerating influence for many miles south- 

 Avards bej^ond the new barrier, the warm current which now 

 penetrates through the straits, and which at other times is 

 chilled by floating ice issuing from them, would, when totally 

 excluded from all communication with the icy sea, have its 

 temperature raised and its course altered, so that the climate 

 of some other area must immediately begin to improve. 



The scope and limits of this volume forbid my pursuing 

 these speculations and reasonings farther; but I trust I 

 have said enough to show that the monuments of the glacial 

 j5criod, when more thoroughly investigated, will do much 

 towards expanding our views as to the antiquity of the fauna 

 and flora now contemporary with man, and will therefore 

 enable us the better to determine the time at which man 

 began in the northern hemisphere to form j^art of the exist- 

 ing fauna. 



